.main {
    width: 55%;
    height: 70%;
    background-color: rgb(241,242,243);
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
}

aside.ant-layout-sider.ant-layout-sider-dark {
    flex: 0 0 15% !important;
    max-width: 15% !important;
    min-width: 10% !important;
    width: 10% !important;
}